Gutted my cat years ago when the state stopped emissions testing cars from earlier than the 1996 model year. I left the empty cat in place so it looks like it is still there. Not much seat of the pants improvement, but without the cat, the exhaust system has to flow better, FYI, I have a 3" DP going into two 2.5" pipes with straight thru mufflers.

Hmmpf. And I just bought a universal catalytic converter, was going to install it myself soon. After 10 years the one Meineke installed started to break up into chunks, the pieces rattling around noise caused me considerable alarm until I figured out what it was. I removed the exhaust pipe and pretty well gutted the cat to eliminate that.

I remember when it was almost as bad here in Phoenix as LA...if you went up into the mountains around here about 20 years ago you could see an ugly tan haze over the city on some days. Theyâ€™ve done a wonderful job in getting rid of that, so I would bet thereâ€™s no way I could pass Emissions here without a working converter. Still, the retest is free if I fail the first time....

Yup have an empty shell under mine. Back in the mid 90's I started to find little metal balls on the driveway, car always passed it's emissions tests even though I was told the cat was hollow as it had blown out all it's contents. I've just left the hollow shell under there, even when I finally replaced the muffler when it went a few years ago.

Since then the car has no longer been required to pass an e-test. One thing I will say is that your exhaust smells a lot more without the cat so for some that might be a reason to have it, otherwise I honestly didn't notice much difference performance wise. I did once I replaced the stock muffler with a Borla, plus it sounds better.